We are pretty sure that the employees of Facebook, and its CEO and founder Mark Zuckerberg, think back of 2012 as a year of ups and downs. The ups included increasing its user base to a whopping one billion active accounts and the downs included the launch of its IPO which quickly saw its stock price plummet to as low as 50 percent below its starting price of $38 a share.

This week, Facebook is apparently trying to start 2013 with a big and mysterious press event. Engadget reports that they and other members of the media will be heading to Facebook's headquarters in Menlo Park, California to attend a press conference on Tuesday, January 15th.

So far, the only clue as to what the company might be working on is the invite itself, which says that the press will "see what we're building." Of course, that kind of phrase suggests something physical and there have been a ton of rumors that Facebook has been working with HTC on some kind of smartphone that has a Facebook theme. Or it could be referring to the code that they are compiling, at this point, it's all conjecture.

Zuckerberg has also hinted strongly that Facebook is actively working on some kind of new search engine technology. A Facebook-powered Internet search engine could be a big rival to Google and Microsoft's Bing, thanks in part to its one billion Facebook user base.